DESCRIPTION

The PKCS#8 functions encode and decode private keys in PKCS#8 format using both
PKCS#5 v1.5 and PKCS#5 v2.0 password based encryption algorithms.

Other than the use of DER as opposed to PEM these functions are identical to the
corresponding PEM function as described in the pem(3) manual page.

NOTES

Before using these functions OpenSSL_add_all_algorithms(3)
should be called to initialize the internal algorithm lookup tables otherwise errors about
unknown algorithms will occur if an attempt is made to decrypt a private key.

These functions are currently the only way to store encrypted private keys using DER format.

Currently all the functions use BIOs or FILE pointers, there are no functions which
work directly on memory: this can be readily worked around by converting the buffers
to memory BIOs, see BIO_s_mem(3) for details.